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Electrical Control of Nuclear Spin Qubits: Important Step For Quantum Computing

Soulskill posted about a month and a half ago | from the now-you're-cooking-with-electricity dept.

Supercomputing 42

Taco Cowboy writes: "Using a spin cascade in a single-molecule magnet, scientists at Karlsruhe Institute of Technology and their French partners have demonstrated that a single nuclear spin can be realized in a purely electric manner, rather than through the use of magnetic fields (abstract). For their experiments, the researchers used a nuclear spin-qubit transistor that consists of a single-molecule magnet connected to three electrodes (source, drain, and gate). The single-molecule magnet is a TbPc2 molecule — a single metal ion of terbium that is enclosed by organic phthalocyanine molecules of carbon, nitrogen, and hydrogen atoms. The gap between the electric field and the spin is bridged by the so-called hyperfine-Stark effect that transforms the electric field into a local magnetic field. This quantum mechanical process can be transferred to all nuclear spin systems and, hence, opens up entirely novel perspectives for integrating quantum effects in nuclear spins into electronic circuits"

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42 comments

hyperfine-Stark effect (0)

Anonymous Coward | about a month and a half ago | (#47186137)

If it depends on any Stark effects, don't expect it to last long.

Re:hyperfine-Stark effect (1)

Bugamn (1769722) | about a month and a half ago | (#47187547)

It works fine to keep powered suits of armor flying.

Pie in the sky (-1)

Anonymous Coward | about a month and a half ago | (#47186169)

Been hearing about quantum computers for many, many years. It still doesn't seem like we're any closer to them than we ever were. I think this is one sci-fi construct that we'll never see. 50 years from now we'll still be doing research into 'quantum computers', and they'll still be generating click revenue.

Re:Pie in the sky (0)

Anonymous Coward | about a month and a half ago | (#47186207)

Yeah right. That is why you can't buy a quantum computer right now, oh wait.

Re:Pie in the sky (0)

Anonymous Coward | about a month and a half ago | (#47186255)

Well, yes, we are still waiting. That's exactly what we have to do, since we can't actually buy a quantum computer at this point in time.

Re:Pie in the sky (1)

Immerman (2627577) | about a month and a half ago | (#47186425)

Sure you can. Well, maybe not you *personally*, they're insanely expensive. And we're not yet 100% certain their computations are actually quantum in nature. But they do seem to exist.

Re:Pie in the sky (1)

retchdog (1319261) | about a month and a half ago | (#47186583)

well, we are 100% certain that the computations are not on the individual quantum bit level. what d-wave claims is to have quantum adiabatic computation, which achieves some quantum speed-up on some optimization problems by (roughly speaking) quantum-parallelizing hill-climbing algorithms.

and it seems so far that they are full of shit, even on that vague claim...

Re:Pie in the sky (1)

retchdog (1319261) | about a month and a half ago | (#47186617)

btw, this was referring specifically to d-wave.

we do have bona fide quantum computers already. it's just that they have so far, at most, 7 qubits, and the registers persist for only ~100 microseconds. but they do exist.

Re:Pie in the sky (1)

Anonymous Coward | about a month and a half ago | (#47186361)

Have a look at: http://en.wikipedia.org/wiki/D-Wave_Systems

Re:Pie in the sky (1)

Anonymous Coward | about a month and a half ago | (#47186399)

If you're going to cite something, at least make the effort to read it fully beforehand!

You must have missed the "Controversy" section of that article: https://en.wikipedia.org/wiki/D-Wave_Systems#Controversy [wikipedia.org]

So there are some serious doubts about veracity of the technology in question.

Had you known this, you probably wouldn't have gone ahead and thrown the link out like you did. If it does anything, it's that it provides significant evidence against what you're trying to argue in favor of!

Re:Pie in the sky (1)

Applehu Akbar (2968043) | about a month and a half ago | (#47186481)

There is an article covering the controversy in the June "Wired."

Re:Pie in the sky (1)

retchdog (1319261) | about a month and a half ago | (#47186613)

we have quantum computers with seven qubits, so strictly speaking we do have them already. scaling seems to be an issue, but progress is being made.

and of course we'll still be doing research into them in 50 years. we're still doing research into classical computers after all.

non-locality or GTFO (1)

globaljustin (574257) | about a month and a half ago | (#47186653)

strictly speaking we do have them already

no.

we do not have the ability to initiate or control quantum entangled particles

to be quantum it must be **non-local**

http://en.wikipedia.org/wiki/P... [wikipedia.org]

Re:non-locality or GTFO (1)

HuguesT (84078) | about a month and a half ago | (#47186783)

No, we really do have working quantum computers in the lab right now. They are fully capable of running Shor's algorithm [princeton.edu] . It's just that they can factor at most a number like 15.

non-locality or GTFO (1)

globaljustin (574257) | about a month and a half ago | (#47186845)

no, we don't have non-local entanglement...I'm not going to have this discussion...it's not true non-locality, at all

please don't start this...it's becoming like arguing about apple vs microsoft

i have a standard response, one that I saved from another commenter...I will post it if I have to

Re:non-locality or GTFO (-1)

Anonymous Coward | about a month and a half ago | (#47187215)

Post it. You're an arrogant moron, no one will take you seriously otherwise. Like, you seem to think you have half a brain, but you're really depressingly average intelligence. And so you are continually spouting shit; the dumb ones are always the most vocal. And while we're at it, use spell check, you illiterate twat.

not for an AC (1)

globaljustin (574257) | about a month and a half ago | (#47188121)

who are you, AC?

a logged in user made the post before me...my comment was directed to them

if that logged-in user wants to contribute to the discussion I'll be happy to post it

Re:not for an AC (1)

retchdog (1319261) | about a month and a half ago | (#47188231)

what? i thought you were "not going to have this discussion". lol.

**INSTEAD OF** (1)

globaljustin (574257) | about a month and a half ago | (#47189137)

if you re-read it you'll see that I refused to have a discussion, and ***INSTEAD*** I would post a standard response that describes, with boring detail, why "quantum computing" is really just "quantum" cryptography

I said I would **post that** instead of have a discussion

Re:non-locality or GTFO (0)

Hategrin (3579025) | about a month and a half ago | (#47188237)

No one would take him seriously unless he's an arrogant moron? Do you take arrogant morons seriously, is "seriously" how arrogant morons should be taken? Wait, silly question, obviously you take them VERY seriously. lmao.

Re:non-locality or GTFO (0)

Anonymous Coward | about a month and a half ago | (#47188585)

If he thinks he can directly contradict the opening sentence of the published journal article by essentially saying, "I know I'm correct, and I shouldn't have to post even a canned response explaining why," he has to either be trolling or thinks that such an approach is actually convincing.

Re:non-locality or GTFO (0)

Anonymous Coward | about a month and a half ago | (#47189627)

no, we don't have non-local entanglement

We do have non-local entanglement and there have been plenty of experiments that work on that topic. That is mostly irrelevant since the point of quantum computing is to implement algorithms that can't be solved with useful scaling on a classical computer. If you want to use your own definition of quantum computer, more power to you, but don't act like you have the one and true definition when it runs contrary to what is used in the actual field, used in the actual paper, and used in textbooks on the topic since it is a simple enough topic to now have intro courses in grad school. There are definitions and names I'm not fans of in the field, but if I try using my own definitions of established jargon in a paper, I would look like an idiot and would be lucky to get the paper published in a half-way decent journal. On a forum, it makes a person look like they have no exposure to the topic at all, regardless of how much they actually have.

Re:non-locality or GTFO (1)

retchdog (1319261) | about a month and a half ago | (#47188205)

what the fuck are you talking about? if you want anyone to listen to you, explain yourself why running Shor's is inadequate to illustrate sufficiency; don't link to a wikipedia article about something you don't understand.

Re:non-locality or GTFO (1)

Hategrin (3579025) | about a month and a half ago | (#47188281)

"non-locality" would be the only thing that would make quantum computing a novel process. Otherwise, it's sort-of like an electric car, using new tech to solve old problems.

If you didn't know, building a "quantum computer" is about more than ramping up the GHz and shrinking die space.

Re:non-locality or GTFO (0)

Anonymous Coward | about a month and a half ago | (#47188571)

Otherwise, it's sort-of like an electric car, using new tech to solve old problems.

Every process you could run on a quantum computer you can run on a classical computer. The mathematics behind the algorithms is pretty straightforward and are not that difficult to program into a regular computer. The only problem is it has horrible scaling and will take a lot of resources to calculate the results for any useful amount of qubits. The entire point of quantum computing is to perform specific algorithms that solve already solvable problems, but with scaling that lets computations in attainable timescales on larger scaled problems. So yes, it is exactly like an electric car in that sense, using new tech to solve old problems faster.

Re:non-locality or GTFO (1)

Hategrin (3579025) | about a month and a half ago | (#47188367)

PS: "Locality" vs "Non-locality" are elementary ideas in quantum mechanics, if you aren't aware of their basic meaning then why should anyone waste their time trying to explain them to you. Do you think the world owes you answers just because you're too lazy to look them up yourself? In the most basic terms these ideas aren't even difficult to understand-- phenomenon that are unexplained by, that contradict classical physics.

For example, one branch of Quantum Computing is projected to accommodate instant network communication across any distances, that is, a network connection to Mars could have a 10ms ping as the connection would rely on entanglement and not radio waves.

Re:non-locality or GTFO (1)

Anonymous Coward | about a month and a half ago | (#47188547)

As someone one with a background in quantum mechanics and who works with uses it as part of my day-to-day research occupation, I'm quite aware of what non-locality is, but don't see why it is necessary for something to be qualified as a "quantum computer." I've seen plenty of arguments about whether something like a quantum annealer counts vs. something that implements more general purpose gates between qubits, but non-locality is not a necessary requirement. Yes, there are some uses in cryptography, but that is its own thing separate from quantum computing goal to implement algorithms with complexity classes separate from what is currently achievable with classical computers.

projected to accommodate instant network communication across any distances, that is, a network connection to Mars could have a 10ms ping as the connection would rely on entanglement and not radio waves.

No, quantum based communications do not allow any transmission of usable information instantly, nor are anything based on quantum mechanics expected to do so as derivable quite easily mathematically from the basic axioms of quantum mechanics. Such instantaneous communication would require quantum mechanics to be fundamentally incorrect. If you are going to chide someone about not knowing basics of quantum mechanics, then maybe you shouldn't follow up by making the most pedestrian of mistakes.

Re:non-locality or GTFO (0)

Anonymous Coward | about a month and a half ago | (#47189237)

You can't use non-locality to transmit information faster than the speed of light. The "signal" cannot be modulated (you cannot force the particle to be spin-up at your end, so you cannot force the corresponding particle to be spin-down at the other end). What does propagate faster than the speed of light is random noise. This was shown by Shimony decades ago.

That description of nuclear spin ... (0)

Alain Williams (2972) | about a month and a half ago | (#47186173)

I read it, but it all just made me feel dizzy!

What has happened to Slashdot? (1)

Anonymous Coward | about a month and a half ago | (#47186281)

As I write this, the parent comment is the only one visible by default, nearly an hour after this submission was posted. Yet it's totally useless.

Meanwhile, there are several good threads of discussion about the actual topic involving Anonymous Coward commenters, yet they're not visible by default.

It's no wonder Slashdot is on its way out. Total crap, like the parent comment, is visible, while the actual discussion is not. It takes effort to show the useful content.

If it's any consolation, at least there's some good discussion going on here, even if it isn't very visible. It's better than the hipster wankfest that Reddit has become, or the totalitarian censorship-ridden shitpit that HN is today.

Re:What has happened to Slashdot? (1)

Immerman (2627577) | about a month and a half ago | (#47186447)

So why are you hiding AC comments by default? And why are you posting as such? I thought it was long understood that a lot of the best comments are posted AC, even if a lot of dreck gets posted that way as well.

Though frankly, I routinely browse at -1 and I'm still not seeing much in the way of decent discussion on this topic.

And incidentally, does anyone know why some comments still vanish entirely? Do they get downmodded to -2 and thence irretrievable oblivion or what? It's really annoying to encounter an interesting heated discussion where the only sign of the missing comment that started it is the indentation.

Re:What has happened to Slashdot? (0)

Anonymous Coward | about a month and a half ago | (#47186895)

Because some people still want to browse the web without Javascript.

Re:What has happened to Slashdot? (0)

Anonymous Coward | about a month and a half ago | (#47186825)

http://slashdot.org/?nobeta=1

hahaah koplakk (-1)

Anonymous Coward | about a month and a half ago | (#47186203)

hahah koplahkkk http://www.muizcyan.co.vu/

Well, duh! (0)

Anonymous Coward | about a month and a half ago | (#47186221)

Come on.

Stumpum Computing (-1)

Anonymous Coward | about a month and a half ago | (#47186357)

Will replace quantum computing. The Stumpum bit is called the stubit, and has seven states, yes, no, maybe, maybe not, I don't know, I don't care, and huh?
N1ALD

Re:Stumpum Computing (1)

graphius (907855) | about a month and a half ago | (#47187955)

This needs at least a +3 Funny

Quantum Cryptography (1)

globaljustin (574257) | about a month and a half ago | (#47186637)

can we **please** stop calling this tech "quantum computing"?

it's factually inaccurate as it does not use quantum non-locality but two independent things that only act as entangled

the application they are developing it for is cryptography

"quantum cryptography" still has "quantum" in it...it still sounds just as cool as quantum computing and its much more precise

Re:Quantum Cryptography (0)

Anonymous Coward | about a month and a half ago | (#47187429)

Pfft... next you'll be telling me that my "Quantum Leap" [old-computers.com] isn't a genuine quantum computer at all!

Re:Quantum Cryptography (0)

Anonymous Coward | about a month and a half ago | (#47188567)

Maybe before trying to convince people on Slashdot that your definition of quantum computer is the right one, you should be send some emails to the editorial board of Science and the corresponding author of the paper since they obviously disagree with you right from the start of the actual article. After that you can work on changing some textbooks and a lot of other articles...

Re:Quantum Cryptography (1)

ceoyoyo (59147) | about a month and a half ago | (#47189947)

Definition? he doesn't even have a definition. Just some jargon he doesn't really understand and a sock puppet to post the really off the wall stuff (Hategrin; instant communication to Mars).

French partners ?? (0)

Anonymous Coward | about a month and a half ago | (#47186925)

For an article written by 4 french authors and 2 from the Karlsruhe Intistute?
Whom first author is a french Ph.D student?
Sure, this article seems to have been written by the Karlsruhe Institute communication department.
However, they could have made some efforts to name all scientists involved and not only the head of the Karlsruhe research group.
   

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